PSI - Issue 68

Boyu Li et al. / Procedia Structural Integrity 68 (2025) 59–65 B. Li et al. / Structural Integrity Procedia 00 (2025) 000–000 3 where the capillary force ( !"# ), water pressure ( $# ), air pressure ( %# ), dynamic pressure ( &# ) and the viscosity force ( '() ) form the resultant force acting on the capillary flow and its mass increment per unit time. The research indicates that the capillary significantly accelerates the water diffusion process in the polymer. However, this is different to the practical situation as shown in Fig. 3. Consequently, this section explores a mathematical approach to the assessment of the influence of the channel shape on the capillary effect in polymers. 61

Fig. 1. Schematic of capillary considered.

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)*%$&+,$-$,

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"#

!

(

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Fig. 2. Forces acting on capillary flow.

!"#$%#$&' (#")*%#+$

,+#(-

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Fig. 3. Transversal cross-section of printed PETG specimen.